Across the stars
by letmesleep
Summary: Mabel's restlessness seemed to get her into trouble often, but this particular time it lead her to discover a creature that isn't so eager in letting her go just yet. Will the goddess manage to break free from the siren's firm hold, or will she succumb to his melodic voice and stay with him forever? Goddess Mabel/Siren Bill Mythical Gravity Falls AU!
1. Chapter 1

Mabel rested among the rows and rows of pink and red roses that gave off an intoxicating scent. The rising sun radiated its warmth on Mabel's pale skin; it was quite a lovely day in her garden. Yet she couldn't help but to feel bored, and trapped in the garden. Grunkle Stannis always told her she should never leave the garden without being accompanied by someone for danger lurked just out past the tree line of the valley. However this particular day Mabel was extremely restless, that is when a beautiful song broke her out of her restlessness.

Mabel looked up to see a beautiful phoenix, its beautiful red feathers faded into a dark orange at the tips, 3 tail feathers were longer then the other feathers, its beak was a beautiful gold. Mabel quietly crept towards it, her breathing shallow as an excitement radiated through her veins. Never in her life has she seen a phoenix, the bird released a sweet melodious chorus that seemed to never repeat its notes, cascading through the branches, tumbling into the crisp morning air, flowing into the surrounding valley side like a great river of music. Mabel stopped, truly this bird's music was fairer then any instrument Robeth could ever play.

Much to Mabel's dismay, the phoenix spread its wings and flew off towards the woods. Mabel ran after it, but stopped at the edge of her garden that bordered on the woods. Her conscience told her not to go, but something inside of her heart urged her to take the first step, and her heart outweighed her conscience this round. A thick morning dew covered the forest landscape. It glistened brightly in the newly rising sun. Mabel followed the phoenix, making sure not to loose it in the dense woods.

The placid water lapped up against her feet as Mabel stood at the banks of the small grotto she had discovered while chasing a phoenix through out a meadow. It had seemed she had lost the bird though, or perhaps it had turned to ashes, no matter Mabel had found this wonderful grotto instead. Looking down at the water one could see everything that resided under the surface. Hundreds of brightly coloured plants grew, and many spectacular fishes as well. She spotted a pink seahorse, its big round eyes, elongated pipe-like snout captivated Mabel's attention.

How peculiar, Mabel thought, as she moved further into the water, it reached her waist when the pink seahorse saw her and swam away. She giggled, the water always intrigued the young goddess, her brother always warned her of the dangers of the water and how she should stay on the land and keep to herself in her garden. Of course she listened him to the most part, but it was boring being cooped up in her garden, she wanted to live before she would be forced to marry the god Giddious. Oh how she dreaded her 18th birthday, he was such a pompous God (more then the rest, believe it or not!) she would rather be thrown to Typhon than marry him. A splash in the water pulled her from her thoughts, she looked across the grotto, nothing had moved. The crystalline water remained calm and un-rippled, but Mabel noticed under the surface the sea creatures swam around frantically. This unnerved the goddess, as she turned to leave the water, but something rooted her in place.

The wind ceased to run through the tall trees and the sky had darkened in despair, a dark chuckled was emitted from beneath the water. Mabel saw something large less than five meters away from her immobile body. She broke into a cold sweat, slowly the thing under the water inched towards her; it was no less than three meters. Tears welled up in her green eyes as she regretted every leaving the safety of her garden sanctuary to chase the dazzling phoenix. When the thing was one meter away it broke to the surface, a beautiful man appeared before her followed by the torso of a snake. A swirl of sickening fear swirled in her stomach, the man/serpent thing smiled at her, she was struck speechless.

"Why have you come to my grotto young one?" The monster's golden eyes pierced hers, "I-I was chasing a phoenix, I did not know that something occupied this beautiful grotto. It is nothing I have ever seen before…"

The creature smiled, showing off its sharp, white fangs, "From where do you come from young one?" Mabel swallowed the lump in her throat, "I come from the valley of the gods, please forgive me of my insolence, I did not know." The creature looked over her, "Very well, I will spare you if you can capture the phoenix that you so foolishly followed here by the rising sun of tomorrow." He said with an almost snide voice.

"But that is nearly impossible! And what if I cannot capture the phoenix? What will happen to me?" She asked wearily, "You will make a delicious meal little goddess. Perhaps it was better that you stayed in your garden, and not let your curiosity get the better of you. After all was it not curiosity that killed the cat?"

Mabel's heart sank to the bottom of her stomach upon hearing that her life was on the line, but she must put on a brave face. " But satisfaction brought it back, I will agree to your terms, but if I will I want to be allowed back in this grotto when I please."

The creature smiled, "I wouldn't mind the company, but that is only if you bring m the phoenix young one." His hand outstretched, and Mabel dainty hand shook his, the size difference was outstanding. "Now go, you have a bird to catch, your life depends on it."

With that Mabel felt her feet be freed from the water, and she ran out of the crystal clear water, determined to find the phoenix. Bill watched the foolish goddess disappear into the dense brush; he couldn't help but to laugh at her pitiful determination to find the phoenix. Although it was never Bill's intention to eat her, it was fun to plant seeds of fear into her heart. Once Mabel was out of his sight, he dove into the depths of the grotto, to his underwater cavern. Once hitting the surface of the cavern, he slithered to where the bones of his past lovers (and meals) resided. Perhaps this one would be different, he would make sure she was different, and she would not get away from him.

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 _Last Gravity Falls AU I swear, as well I was inspired by_ _eternal1990's siren Bill stories._

 _ALSO who did this artwork?(The cover page) I'm_ _trying to find who did it but I can't and I WANT TO GIVE CREDIT WHERE CREDIT IS DUE SO HELP ME GUYS!_


	2. Chapter 2

The hours droned on, the sun was hang low in the in the sky while the warm humidity of the woods made her feel sticky and suffocated. Her wet dress clung to her body, and hair, slick with perspiration. Sweat rolled down her skin in thick, salty beads. She could feel her heart throbbing inside her chest. She was heading east, but she had no idea where the phoenix could be, for all Mabel knew it could be heading west.

How foolish of her to not listen Stannis! Now she was doomed to find a bird because of her act of rebellion, or worse eaten by that monstrous creature! Mabel scanned the trees; there was no sign of the bird anywhere. Mabel followed a path that was intertwined with thick tree roots. The light that beamed through the tree foliage was green. This hidden path was tucked away, in the depths of the forest. It swerved back and forth unpredictable. The path was remarkably clear, for one that Mabel assumes was so rarely traveled. Mabel took a minute to admire the beauty before going back to the task at hand.

If she couldn't find the bird by sunrise she would surely be eaten… but she didn't have to return to that grotto did she? She couldn't disregard her deal, she must return to that creature. "Little goddess do you waver from your deal?" A wispy voice called, Mabel looked around, she couldn't see anyone. "No I am not wavering from my deal." Mabel called out fiercely, "Alexander! Did you catch it?" A young voice chimed, " Yes, Yes! I have caught the phoenix!"

Mabel's eyes lit up, her heart soared as she saw two boys in the forest's clearing holding a cage with the phoenix inside. Mabel quickly strode to the boys, who looked up and gawked at the goddess. Mabel towered over the boys; they were roughly around 5'2 while Mabel was at least 6'1. "Greetings young one, I see you have caught my phoenix."

"Oh we did not know it was yours miss, we are deeply sorry." The black haired boy stammered, "It is fine, I had left its cage open and it flew off you see. I was looking everywhere for my beloved bird. May I please have the cage?" The blonde boy looked at his black haired friend, before nodding. " Here you go, we are sorry."

Mabel let off a laugh, "Do not be sorry young ones, for your help in finding the phoenix I will both give you two these seeds. By planting them, your crops will never wither through drought or flood. There will always be plenty to harvest, my deepest thanks." Mabel conjured up two sacs full of seeds for the awe struck boys, she handed them to the boys, and in return she received the phoenix. "Now you best be off, there are many dangers that lurk in these woods." She said grimly, referring to the creature she had encountered at the grotto.

With that the boys thanked her once again, and scampered off into the woods on the other side of the field. Before emerging into the tree line, she looked up to the sky, last vestiges of the setting sun disappeared over the sleepy mountains, the copper hues giving way to a dusty purple scattered with the occasional glitter of a faraway star. Never in her life has she seen stars that shone so bright, the distant skyline stood silhouetted against a velvety sky, the golden dusk enveloped by the twilight sky.

The phoenix cooed, as the duo headed into the woods, sadly underestimated the utter blackness of night-time in the woods. With the fleeting light, Mabel tried to make her way through the forest; the phoenix illuminated a soft glow on the trees acting as a lantern to guide Mabel's way. The wood was dark and foreboding, but there was peace in its sullen ambiance. Mabel's eyes flickered over the thick, dark trunks of the trees that rose steadily into the sky, its branches interlocking with its neighbours like giant's arms linked together protecting their home. The trees were densely packed together, leaving just enough space to allow someone to manoeuvre through. Mabel pressed her free palm against a tree's rough bark, and breathed in the scent of the woods. She enjoyed her freedom, but she must return to the grotto with the phoenix. The musty scent of leaves after rainfall, the warm soil packed against the earth by scurrying animals, the scent of things in different stages of blooming and growth. This smell of life, the forest was teeming with it. This is what she ruled this was her kingdom.

Mabel walked for the rest of the night, her strides slower, as exhaustion took over her body. In the distance she could hear a bubbling stream, excitement filled her body; turning to the sky Mabel saw that dawn was fast approaching. She hurried on the path as she saw the suns rays creeping up, casting long shadows across the ground. Mabel could see the clearing with the creature waiting on a rock; his face was a mixture of surprise and anger.

"I'm here!" Mabel called, running to the grotto, "I have the phoenix you asked for!" Mabel said breathlessly, the creature eyed her as she ran to him, the sun almost in the sky. "Indeed you did young one, but you must give me the phoenix. Not simply bring it to me." Mabel paused, looking at the creature on the rock in the middle of the grotto. Mabel quickly summoned some vines to make a bridge across the grotto. She balanced on the narrow bridge, clutching the cage tightly as she was safely on the rock. "Here." Mabel said, holding the cage to creature, it took the bird and laughed at her. "Congratulations young one, you caught the phoenix, but you were unable to bring it to me on time, the sun has already risen."

Mabel took a step back, feeling her dress in the water. "You are lying, I was on time!' Mabel hissed, looking frantically at him. He chuckled, slithering towards her. "Hush now young one, I don't want you to fall into the water. After all you can't swim can you?" Mabel was taken aback from how the creature knew about that, "Y-You tricked me, you knew I wouldn't have time if you where on this rock." The creature's smile widened, "Indeed you are! You are a smart little goddess."

"You monster!" Mabel screamed, causing some animals in the forest to run away in fear, "I prefer the term siren, little one." The siren cooed, approaching Mabel, "Shhh, it is okay. I am not going to harm you." Tears began to well up in her eyes, " Liar! I gave you what you wanted, I was so close." She cried, she quickly turned to her vine bridge. She only got half way to dry land before she felt something wrap around her ankle and she fell into the crystal clear water. Water filled her lungs, as she waved her arms frantically. The weight of her shoulder plates and her hair were pulling her down to the bottom. Mabel struggled to gasp for air, her head bobbing above the surface, gasping for air. Her head was pounding, every cell in her body was screaming for oxygen.

She felt arms around her waist and the siren pulled her further into the depths of the grotto. Soon she felt her body go numb, and she cursed herself for how stupid she had been to leave her garden.

Dipper scanned his sister's garden; there was no sight of her. Fear crept up his spine, as the God of wisdom walked further into the well preserved garden in search for his sister. "Mabel! Where are you?" Dipper called, but he never received a response. He turned to go find Stannis, worry prevalent on his face.

Mabel awoke inside a small body of water that appeared to be inside a cave… or maybe a cavern of some sort. The place was littered with tiny sparkling crystals not unlike the stars of the night sky; they were so mysterious, "I see you are up little goddess." The siren said, slithering towards her, Mabel tried to get up, but her legs felt heavy and she couldn't seem to kick them. "What did you do, why can't I move?" Mabel screeched as the siren leaned down to cup her face, Mabel dug her nails into his wrists, he seemed unfazed by it though.

"I thought to myself why eat such a beautiful goddess? When I can keep her for myself, so I did just that. But I couldn't keep you if you were able to run away, so I gave you a tail, my little mermaid." Mabel's eyes widen, her face contorted into something of horror as she broke free of the siren's grasp, dunking her head underwater to see a beautiful pink tail in replace of her legs. "Please change me back, please! I beg of you, please." Mabel said distressed, clutching the edge of land before the siren. "Do I need to sing to you to calm you down?" The siren purred, "Don't you dare, I am a goddess, a higher being then you- you siren, wicked cre-" The siren put a finger to her lips, "Hush little one." The siren cooed, before he began to sing, the song was irresistibly sweet, yet it was laced with sadness and grief d in their words. The melody purred to her soul, piercing through and engulfing the goddess's entire being from within.

Her body felt limp, as her eyes drooped, and the siren's arms wrapped around her waist and pulled her around the small body of the water, lulling her to sleep.

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 _Please read and review! I own nothing_


	3. Chapter 3

Dipper searched high and low in the valley and the surrounding mountains, but with no avail. Each day he would return back to the valley of the Gods without his beloved twin sister. Many goddesses speculated that Mabel had run off to elope with a human male, or she fell into the clutches of the siren Bill Cipher. Dipper had had a couple of encounters with the siren, at first he was acting very friendly towards the young god, interested in hearing more about his family… Mabel! How could he have been so stupid, the siren used Dipper to learn about Mabel. Dipper speculated Bill wanted to use her powers somehow. Grabbing his sword he knew where he had to go next, the siren's grotto. He cut through his sister's disheveled garden, it broke his heart to see the once vibrant plants limp and somber. Weeds slowly invaded the flowers, and apple trees, he needed to get Mabel back.

There were days she craved the shore, she laid her chin against a rock staring at the sand. The tide would draw a breath and hum deeply; crawl along the sand on its belly, stretching itself thin until it was an inch, then drew away back into the water in which Mabel resided. The sun beat down on Mabel's back, as her tail resided in the cool water of the grotto. The siren had taken her out of the underwater cavern grotto to the grotto where she had made that fateful deal, "Little one come here." The siren purred beckoning her to where he was sitting on the rock, she looked at him with hate; "No" she said bitterly and slowly retreated further back into the water with the fish. "Do I have to sing?" The siren said, sitting up.

Submerging the rest of her body under the water, Mabel swam further down into the grotto to avoid the sirens melodic voice. She covered her ears, as she felt the siren wrapped his arms around her torso. " _The fair maiden crossed the sea to be with me, across the stars where Venus resided to be with me~"_ The siren said in his wickedly beautiful melodic voice, it pierced her ears like beautiful waves that lapped the sand that she longed to walk on again, her body stopped struggling and began to relax. "Please stop! Haven't you done enough?" Mabel begged, wishing she could cry once again, "I've think you've had enough sun for now. Come pet."

Mabel pulled herself from his grip and slapped him across the face, before moving back. Her green eyes glowing beneath the depths; baring her sharp fangs, "I am not your pet, I am a goddess! I demand you release me and return my legs!" Mabel screamed, the siren just fixed his cold gaze upon her. It felt as though the water had dropped in temperature significantly, and all the lush vegetation dulled in colour. Mabel wanted to move, but her body felt stiff under the siren's gaze. She regretted saying things; she said perhaps it would be better if they were rather left unsaid. "You are such an ungrateful brat. No matter you are not going anywhere! A deals a deal little goddess." Mabel tried to swim away but the siren grabbed her tail and began to drag her back to the cavern where she was kept.

The siren waved his hand creating a small river for Mabel to swim through to return to the small grotto in which Bill forced her to reside. Once Mabel was in, the river disappeared. "Dipper will come for me, and when he does you will be sorry." Mabel said knowingly, praying that her brother would notice her absence in the garden by now. He laughed maliciously, slithering into the water, "You think that little god is going to save you?"

Mabel swam back, "Stay away from me." Mabel said wearily. "Or what? You are going to run away. Little goddess you are not going anywhere, this is your home now, and you are mine." He said, wrapping her tail with his, his hands tangling themselves in her long brown hair. "Please, what do you want from me. Just kill me if you have too, but I can't play this game of yours." Mabel said, practically pleading to the siren. "But shooting star, you've been playing everyone else game. Trapped in the garden, everyone always telling you of the dangers of the outside world, and if I'm not mistaken being forced to marry Giddious? Stay with me shooting star! I can give you everything your little heart desires."

The siren said, taking his hands out of her hair and conjuring up a beautiful necklace with a golden chain and a beautiful emerald in the center, two purple gems were placed on both sides of the emerald as well. Mabel was captivated by the shininess of the necklace, a trait she picked up being a mermaid. "You are my shooting star, to brighten up my starless sky." The siren whispered, putting the necklace around her neck, "They love me, that is why I must return." Mabel whispered, captivated by the silence. " What if I told you that I loved you?" The siren said, caressing her cheek, "I would say that you are a liar, you are not capable of understanding love. Your voice is your mistress, and you are bound by your thirst for blood." Mabel spat, his smile widened into something of wicked satisfaction.

"Some people say I'm evil, but I say I'm just different. Gods look at a human and see something cute, but I see something I can kill. I don't want to just kill them though; I want to see how long it can last while I disembowel them nice and slow. I want to see the light go out in their eyes while I examine their innards. I could say it's for my morbid curiosity, but that would be a lie. The truth is I enjoy it I get a kick out of it, I want to be feared, but it does get lonely here." The siren said, pulling Mabel closer to him.

He looked at her like a cobra seeking it's prey, wide eyes golden with black pupils as inky pools, hardened features, his golden hair slicked back, deep shadows under protruding cheek bones. Looking in his eyes she could see the evil glint in the siren's eyes. With slow movements he moved them around the tiny grotto, a bright false smile spread across his featured acting suddenly friendly. "There is no love in fear, siren." Boldly speaking, she pushed herself away from him only for his tail to wrap around her waist and bring her back. " Fear is love, love is fear. Don't confuse yourself little one, and do not tell me that the gods do not create havoc among the humans only for them to worship you. We are no different."

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 _I wanted to write more for this chapter, but I like how this ended for now. Please read and review._


	4. Chapter 4

The river was a slice of mellow harmony amid the fragrant leaves. It flowed like time, always onward, always toward its destiny, or was it Dipper's destiny. H knew these placid waters would enter that great sirens grotto. Dipper couldn't kill the siren with his sword, he knew that much, but he would hope it would hinder the siren for just enough time. Walking through a clearing he saw his destiny had arrived. Dipper stood at the edge of the grotto, eyeing the crystal clear water carefully, prepared for the siren to strike at any second. Hate burned in him so deep that it was ingrained in the tissue it was welling up in his heart, fury itself burning him up. "Siren! Show yourself." Dipper said with a mighty roar, waiting for the beast to emerge. Slowly the water started to ripple as a figure slowly rose out, Dipper raised his sword waiting to make the blow. "Dipper?" Mabel called out from the water, "Mabel, you are live!" Dipper screamed, lowering his sword. "Dipper it's not safe for you to be here, you need to leave now." "What are you talking about Mabel, I'm here to save you. Come on lets go." Dipper said pulling on Mabel's arm, "Dipper I can't leave, I don't have legs anymore." Mabel pulled herself up on the edge to show her pink tail to the gawking Dipper. "What did he do to you?" Dipper said in a state of disbelief, "I lost Dipper, there is no hope for me, go before he comes back." "I'm not leaving you her like this."

"Well, well, well, well, isn't this touching? I leave you alone for an hour and we have a guest, oh and if it isn't Pine Tree!" A smug voice said from behind Dipper, "Dipper run!" Mabel hissed, but Dipper didn't budge. "I'm not leaving until you give me back my sister you fowl beast." Dipper snarled, the siren slithered around Dipper, eyeing him up hungrily. "Why have you come here little pine tree? Do you wish to die?" The siren said, and he swiped at Dipper, "No!" Mabel shrieked, forcing herself out of the water to stop the siren. As soon as her tail left the water her throat burned, her heart began to hammer in her chest as she tugged on the sirens tail. "Spare him…" She pleaded, black spots forming in her vision, "Mabel!" Dipper screamed, wanting to help his sister, but know it would put him at a disadvantage.

The siren looked down at the gasping mermaid, his heart lurched as he scooped her up creating a water collar to cover her gills, "Pine tree, let us cease this fighting, I'm sure we could work out a little deal?" Dipper eyed him with caution, "What did you have in mind?" Dipper said, fully aware of the sirens lies and trickery. "If you are willing to retrieve me the golden rift, I will be more than willing to give you Shooting star back, but if you fail she stays with me." Dipper pondered this, "I want Mabel with by my side then, with her legs back." "Very well shake my hand, make the deal, then leave, and you'll have your sister back once you exit the clearing."

Dipper hastily shook his hand, "I'll be waiting for her, if she's not by my side in an hours time I'll have your head. "My words are honest Pine tree, now go" Dipper resentfully turned around and left the grotto, once the siren saw that he was out of sight, he looked at the mermaid in his arms, he dropped her to the ground and mutter a spell. Slowly her tail transformed into two legs, Mabel covered herself as she looked up at the siren. "I-I need clothes." Mabel muttered, a blush creeping across her face, "I can see that." Bill purred, conjuring up a simple white toga, "Put this on, I'll turn around." Mabel waited till his back was turned before putting on the toga, once she was done he instantly faced her. He pulled her wrists closer to him, "Listen here little mermaid, you are mine, and mine only. It is only if Pine tree and you get the golden rift will you be free, but if you fail to find it by the next full moon you will come back to my grotto and you will stay here forever." Mabel could only nod as she turn and ran out of the grotto and through the forest.

The cheers and claps of the feast put Mabel into a trance, normally she was the life of the party, but tonight she just was a mouse peering through the keyhole, "Do you miss me? Come back to me, I miss you." A voice in her head purred, she pressed to ignore it. "Mabeline, come here Dandidus is telling us a story about the siren!" Canthena said with a smile, fixing her glasses, for the goddess of literature she could sure be dumb at times.

The fire was lit and the atmosphere was that of mystery and suspense. "Along time ago there lived a God by the name of Bill Cipher, he was the God of mayhem and trickery, boy did he ever live up to his name. He was all-powerful, and ruled our realm with an iron fist, striking terror into the hearts of the mortals. Until one day the 5 Gods formed a spell so powerful it bound Bill to a torso of a snake, and losing most of his powers. This all came at a price, one day Bill will once again regain his powers and walk among the Gods again." Mabel's blood went cold; the thought that Bill was all-powerful was a terrifying image, a sinister chuckle came from inside her head. You will be my queen when the time comes. "What about the golden rift, what is that?" Mabel said from the soft velvet couch she laid on, "Ah yes the golden rift, it is a book with incantations from the beginning of time! Such knowledge that even we can't comprehend, it is said to be in the depths of the underworld." Mabel's heart sank; there was no way for Gods to go into the underworld without the help of the Valentino's scissors. Mabel glanced over at Dipper; it appeared he was thinking the same thing. As the fire dwindled, Mable stayed behind with Dipper, under the veil of night they came up with a plan to steal the scissors to go retrieve the book. "We shouldn't do this Dipper, I should just return to bill." Mabel said frustrated, pulling at her hair. "We can't give up, we have to find this book!" Dipper said exuberantly as he gave Mabel a warm smile. "But you heard what Dandidus said, what if this book is Bill's key to regaining his power Dipper? Our world would be destroyed!"

Destruction was something he was well too versed in the art of; he slithered along the floors of the cavern coming to a secret room, which contained the three items that he needed to regain his power. The tear of a mermaid, the eye of the Cyclops, and a strand of hair of a goddess, now all he needed was to stall the Pine spawns. He wanted it to be a surprise when his little goddess came back to her world flipped upside down. It was only a matter of days before the full moon will rise, and so will the gates of his nightmare realm and his reign once again. Only a matter of time…


End file.
